sci-tech

Strengthening the battle against cancer

Unique finding from Sri Lankan Scientists:

Dhaneshi YATAWARA

Healing cancer or even controlling it, is considered to be a miracle. Hence, new medicines, compounds, methods etc flow into the Medical science field almost every day. To the world, with its present levels of pollution, dealing with cancer have become vital.

Lichen - Usnea species

Asparagus

Nigella sativa seeds

Coriander

Sri Lankan science field shows no exception. Sharpened with many trial and errors, several local scientists have revealed many important findings to strengthen the fight against cancer. The revelations are unique and definitely with extended support on to these scientists these novel concepts could stand significant in the international science arena. In one research, funded by National Science Foundation of Sri Lanka, a group of scientists found anti-cancer compounds in lichens of the Usnea species. This research group of the Peradeniya University, headed by Professor Veranja Karunaratne, discovered the most potent and promising anti cancer compound to be discovered from any land or marine source of the country in these specific lichens found in Ambewela.

The research work of this project was undertaken to explore the potential of Sri Lankan lichens, a hitherto unexplored source of new bio-active compounds.

Lichens are mutually benefiting associations of a fungus with another plant, usually a green algae or a cynobacterium that can produce food for the lichen from sunlight. In the natural environment, lichen provides the algae with water and minerals that the fungus absorbs from its substrate. As for the algae, it uses the minerals and water to make food for the fungus and itself.

The researchers collected the bio-active compound of four lichens, separated and purified. The group was able to extract three compounds from the chemical extract of Usnea type lichen collected from Ambewela. Two of these compounds, named Ambewelamide A and Ambewelamide B, were found to be new members of a family of highly modified chemicals and are the first examples of this family of compounds isolated from a lichen.

Researchers found that Ambewelamide A showed anti-cancer properties along with anti-fungal activity, more active than certain commercial preparations and mosquito larvicidal (mosquito larvae killing) ability.

The National Science Foundation stated that a Canadian patent application was filed based on the promising bio-activity of this compound.

The third compound separated from this lichen namely Usnic Acid, have shown anti-termite activity in addition to antifungal and mosquito larvicidal ability. Another highlight of this research program was the organisation of the first ever National Work shop on Sri Lankan Lichens, in May 1999.

Ayurvedic miracle

In two other researches, funded by the National Science Foundation, proved anti-carcinogenic properties of ayurvedic decoctions, especially for liver cancer. Liver cancer is rated as the eighth leading cause of cancer deaths worldwide. According to medical experts, B and C types of Viral Hepatitis infection or cirrhosis associated with alcohol consumption are the two major causes of liver cancer.

In a research jointly carried by the Bio-chemistry departments of Universities of Sri Jayawardanepura and Kelaniya, scientifically tested anti-cancer properties of some herbal extracts used in traditional Ayurvedic medicine. Dr. Nalini Wickramasinghe, formerly of the Faculty of Medical Sciences of the Sri Jayawardanepura University and Professor Ira Thabrew formerly of the Department of Bio-chemistry and clinical chemistry, Medical Faculty of the University of Kelaniya jointly carried the research.

In ayurvedic medicine, several plant based treatments are being recommended for cancer. But, none have been subjected to a proper scientific testing so far.

In this typical research, a decoction that contained black cumin seed (Nigella sativa or kalu duru), root of Indian sarsaparilla or iramusu in Sinhala and 'arakkan' in Tamil (Hemidesmus indicus) and rhizome of Chinese sarsaparilla (Smilax glabra) was prepared according to the methods recommended by traditional ayurvedic medical practitioners to cancer patients.

This decoction was tested for protective effects against chemically induced cancer of the liver in laboratory rats. A normal medicinal dose and a higher dose of this brew were tested on cancer induced rats. Researchers found that though the overall result indicated that the anti-cancer effects of the medicinal dose were good, it was better with a higher dose.

Tests also confirmed that there were no toxic effects of the decoction on the liver, kidneys, lung, heart, stomach and gut. Blood components showed no affect by three months treatment of this decoction. In addition, no unfavourable effects were seen on the fertility and breeding of both male and female rats. The three month long treatment of this decoction showed no change in food intake, average body weight gain and general behaviour of the animal. It also showed even given in 40 time stronger dose than the normal it did not cause any deaths in rats.

In another study done by Professor Chitra Pathirana of Bio-chemistry department of the Medical Faculty of the University of Ruhuna showed liver healing properties of five common herbal plants used in traditional medicine in Sri Lanka.

Studies were carried out on mice to scientifically evaluate the claims of traditional medical properties of five herbal plants believed to have anti-toxic effects on the liver. Two liver toxins were selected for the study - i.e. Carbon Tetrachloride and Paracetamol. An over dose of Paracetamol can damage the liver. Damage caused by Carbon Tetrachloride was similar to that of viral hepatitis.

The plants were Neeramilliya (Asparagus falcatus) Heen Mudumahana (Epaltes divaricata), coriander (Corriandrum sativum) and sevendara (Vertiveria sp.). Extracts of these plants were fed in to laboratory mice both before inducing liver injuries and after using the two liver toxins. Liver enzymes and pathological changes were studied to find out the effects. The overall result of this study showed that all five plant extracts have some ability to protect the liver against injuries caused by over dose of Paracetamol and Carbon Tetrachloride. The level of protection shown, varied among the different plant extracts.

The importance is that though there are few drugs used in treating liver diseases they are costly and can often be not very effective. In addition they have side effects. Therefore, the search for safe, inexpensive, alternative liver protective drugs is a major requirement. It was claimed that traditional medicinal herbs have remarkable ability to restore liver health.

Reducing risk of liver cancer

Garlic has been used both for cooking and medicinal purposes in many cultures for thousands of years, dating as far back as the time that the Egyptian pyramids were built. It is well known that garlic contains substances which are important for human health.

Among many other claims garlic is thought to help prevent heart diseases, high blood pressure, and cancer as well. Since including garlic in the diet reduces blood cholesterol levels in normal and high cholesterol individuals, several commercial forms of garlic such as garlic tablets are used for the treatment of high blood cholesterol.

A study, funded by a grant from the National Science Foundation, was undertaken by a team of scientists from the Department of Biochemistry, University of Sri Jayewardenepura to find out whether treatment with medicinal doses of garlic reduces liver cancer caused by chemicals in normal rats, and in rats with high cholesterol levels.

The study looked into the claims of anti-cancer properties of garlic using laboratory rats. A daily treatment of a medicinal dose of oven-dried, powdered garlic was given to normal laboratory rats for two weeks.

These rats were then injected with a chemical (DEN) to induce liver cancer in them. Garlic treatment was continued for eight more weeks. While another group of rats were given only DEN (no garlic), a third group of rats were given only garlic (no DEN). The livers of all these rats were examined for the growth of cancer. Those given DEN had developed cancer of the liver but the DEN plus garlic treated rats showed a remarkable lowering of the cancer formation in their livers. This study proved that garlic reduced the risk of liver cancer in normal rats.

A similar study was carried out on three groups of rats with high cholesterol. This study verified again the preventive properties of garlic on liver cancer. It further showed that the risk of development of liver cancer was higher in high cholesterol rats than in normal rats. Therefore, rats with high cholesterol levels were more prone to liver cancer.

This study, substantiates that garlic can reduce the risk of liver cancer and thus inclusion of garlic in our diet may be important for cancer prevention.

Gliricidia, the multi-purpose alternative crop

Gliricidia species or better known as wetamara was identified as a multi-faceted plant ideal for the tropical climate of Sri Lanka. Hence, Gliricidia plantations were started to be used as an inter-crop with coconut, tea, and different short-term cash crops. The use of Gliricidia foliage as cattle fodder and organic nitrogenous fertiliser became very popular in the agriculture sector.

The technology for using Gliricidia as fuel, fodder and fertiliser crop has reached commercial scales in Sri Lanka.

Thus, realising the national benefits and its potential in Sri Lanka the Government declared Gliricidia as the fourth plantation crop in the country.

Recognising the importance of this lush green tree, a team of scientists conducted a research program to determine the maximum that could be exploited from the gliricidia species. The former Chancellor of Moratuwa University, Vidya Jothi Dr. Ray Wijewardene, Director of Alternative Energy Division of the Ministry of Science and Technology, P.G. Joseph, President of the Bio Energy Association of Sri Lanka and the Head of the Agronomy division of Coconut Research Institute Engr. Parakrama Jayasinghe and the Chairman of the Coconut Cultivation Board Dr. H. A. J. Gunathilake were the members of this research team. Realising the need to develop indigenous resources in meeting the country's energy needs, a research program was conducted by them to determine the optimum parameters for Short Term Rotation Coppice (SRC) energy plantation suitable for the degraded marginal lands in Sri Lanka.

It has been identified that these SRC energy plantations were the most suitable for the degraded marginal lands in the country. The National Science Foundation presented a special award to this unique research at the 2008 National Science and Technology Awards ceremony for the contribution it made to the development of eco-materials/eco friendly processes for industries. Researchers conducted experiments using Gliricidia sepium trees at twelve different locations in the country.

The optimum results were obtained from these trees planted at a spacing of 1 metre x 1 metre and harvest was collected at six monthly intervals. The researchers point out that by extending the Gliricidia plantation to underutilised lands, the country's dependence on imported fertilizer could be largely reduced.

In addition, our dairy industry could also be improved to meet our national needs of milk and other dairy products. At present 75,000 tonnes of Gliricidia foliage per annum is being used as fodder as well as fertilizer replacing 1500 tonnes of urea.

According to the researchers, at present, 10 off-grid electricity generating projects with a total capacity of 130kW have been established. Converting Gliricidia branch wood into producing electricity or industrial heat was another successful invention. Hence, 15 industrial institutions have initiated energy producing projects by using Gliricidia, instead of petroleum fuels.

According to the statistics its can save 18,000 tonnes of oil per annum. This shows that a large proportion of grid and off-grid electricity could be generated with indigenous fuel. The country could eventually generate all the heat, energy requirements, etc., reducing the need to import petroleum fuels.

(DY)

New devices to halt electricity wastage

UoM, NSF in joint effort:

Street lamp controller

Ceiling fan controller

The demand for energy in Sri Lanka has increased steeply over the years. The total capacity of the country's electricity generation system is rising each year at an approximate rate of 8%. This is expected to grow at around 10% annually during the next decade mainly due to energy wastage in the industrial, commercial and domestic sectors.

Reducing energy wastage is the main force behind a sustainable electricity supply. A research team headed by Professor K. K. W. Perera of the University of Moratuwa, funded by a grant from the National Science Foundation, has developed three electronic devices that could help save electricity.

Switching-on-and off of street lamps in most places in Sri Lanka is done manually and it is quite often possible to see street lamps not switched off even at mid day. This project has developed a low cost electronic controller for automatically switching on and off of street lamps. The principle, although widely applicable to street lighting can also be used at home.

According to the researchers these automatic controllers can save about an hour's electricity everyday by promptly switching off unnecessary lights. The device needs no additional wiring. Being completely solid state it has no mechanical components. The device consumes very little energy and is highly reliable and requires hardly any maintenance.

The second device is a timer for ceiling fans. Although timers are commonly found in many industrial and domestic equipment, timers have not been incorporated into a ceiling fan regulator. The researchers have incorporated an Auto Timer Controller in a ceiling fan regulator. The timer can be set at the time of going to sleep so that it will switch off the fan at a preset time. In addition to saving energy it would avoid inconvenience of having to get up to switch off the fan. The device can replace the normal fan speed regulator. No additional wiring is required. It can also be useful in offices where fans could be switched off at the end of work.

The third device is an Alarm to indicate unnecessary use of electricity with an optional tripping facility. This device sets off an alarm to warn the user when excessive lamps or equipment are switched on. The level of current at which the alarm should go off can be pre-set based on the requirement of the household.

Thus, the user could be reminded to switch off some lights or other devices and reduce his electricity bill. Such a device would also be invaluable to save electricity in an office or any other industrial site.

'Courtesy: National Science Foundation of Sri Lanka

Straw fertilizer boosts rice yields

For more than four decades, high yielding rice varieties were widely grown with the use of chemical fertilizer in all rice cropping systems of Sri Lanka. However, yield stagnation of rice was recorded in many parts of the island in the early 80's, partly due to the decreased fertility of rice soils.

It has been shown that adding rice straw at a rate of 4 tons per hectare could provide the total potassium requirement and 30% of the nitrogen requirement of the rice crop. But, recycling of rice straw is not practices by many farmers mainly due to high labour costs involved in transport straw to the field and the difficulty in harrowing and ploughing the field in the presence of fresh straw.

Under natural conditions, fresh straw should undergo decomposition for a period of about a month to become brittle. The slow decomposition of rice straw is due to its high lignin and cellulose contents. The best option to overcome this situation is to have the straw decompose quickly. Only a few types of bacteria and fungi can decompose cellulose and lignin in rice straw. Therefore, speeding up of the decomposition process of rice straw by introducing such organisms would help overcome difficulties arising in land preparation for paddy cultivation.

Microbiologists from the Faculty of Agriculture, University of Peradeniya have isolated indigenous soil bacteria and fungi that can accelerate the decomposition of rice straw in wetland rice fields. Inoculant mixtures have been formulated with several bacteria and fungi. These inoculants can be recommended for fresh rice straw from new improved varieties used in wetland rice fields.

The mixed inoculants of bacteria and fungi isolated by the researchers decompose straw rapidly with a weight reduction of up to 50% in 20 days.

The decomposed material was also found to be high in nitrogen.

Incorporation of composted material in rice fields increased plant growth, number of tillers and yield under field conditions. Since these inoculants performed equally well, the field tests conducted at Kegalle in the absence of chemical fertilizer, and at Peradeniya in the presence of chemical fertilizer they could be recommended for both production systems.

(Research funded by Sri Lanka National Science Foundation)